<?php

require_once 'HTMLPurifier/AttrTransform.php';

/**
 * Post-transform that copies lang's value to xml:lang (and vice-versa)
 * @note Theoretically speaking, this could be a pre-transform, but putting
 *	   post is more efficient.
 */
class HTMLPurifier_AttrTransform_Lang extends HTMLPurifier_AttrTransform
{
	
	function transform($attr, $config, &$context) {
		
		$lang	 = isset($attr['lang']) ? $attr['lang'] : false;
		$xml_lang = isset($attr['xml:lang']) ? $attr['xml:lang'] : false;
		
		if ($lang !== false && $xml_lang === false) {
			$attr['xml:lang'] = $lang;
		} elseif ($xml_lang !== false) {
			$attr['lang'] = $xml_lang;
		}
		
		return $attr;
		
	}
	
}

